Low-dimensional hard magnetic materials

When a piece of ferromagnetic material reduces its size to nanometer scale, its magnetic ordering will be altered and its magnetic properties will be consequently changed, because ferromagnetism is a size-sensitive physical phenomenon related to electronic exchange, magnetocrystalline anisotropy, and magnetostatic interactions, which are all effected by geometric parameters of the material at nanometer scale. In this review, we systematically discuss the scientific and technological problems of low-dimensional ferromagnetic materials, from their synthesis strategies to the geometric confinement in fine nanoparticles (0D), nanowires (1D), and thin layers (2D) that give rise to new magnetic effects, including the size, surface, and shape effects on magnetic properties, particularly on magnetic anisotropy and coercivity. Various ferromagnetic materials are studied, including metals, alloys and ceramics. These low-dimensional nanoscale magnets can find broad applications in green energy, information storage, and biomedicine. On the other hand, low-dimensional objects can be used as building blocks to assemble new types of advanced 3D bulk magnets. Research in this area is significant not only for technological applications but also for a fundamental understanding of magnetic anisotropy and interactions.

Automated summary

When ferromagnetic materials reduce their size to the nanometer scale, their magnetic ordering and properties change due to size-sensitive physical phenomena. This review discusses the scientific and technological problems of low-dimensional ferromagnetic materials, including their synthesis strategies and the effects of geometric confinement on magnetic properties. These materials, including metals, alloys, and ceramics, find applications in green energy, information storage, and biomedicine. Research in this area is important for both technological applications and understanding magnetic anisotropy and interactions.